1. Field of the Invention
The present invention relates in general to the field of mechanically-joined structural assemblies.
2. Description of Related Art
It is desirable for a structural assembly to efficiently transfer loads (e.g., shear loads) across one or more joints between components of the assembly. Furthermore, in many structures it is preferred that the loads be substantially uniformly transferred through the entire structure. Failure to efficiently and uniformly transfer loads often results in a structure being subjected to stresses concentrated in localized portions of the structure. Such concentrated, localized stresses may exceed the design criteria for the structure, even though the overall loading on the structure is within design criteria.
It is particularly desirable for a structural assembly that includes one or more adhesively bonded joints to efficiently transfer loads, especially shear loads, across the bonded joints. If the adhesive bond fails due to concentrated stresses in a particular portion of the bond, loads will no longer be efficiently transferred between the members joined by the adhesive bond. As a result, adhesively bonded primary structure is disregarded from consideration in many applications, such as aircraft applications.
Moreover, it is desirable for fastener openings or holes to be generated in parts at a detail fabrication stage, rather than being match-drilled as the parts are being assembled. Conventional manufacturing methods used to drill fastener holes during the detail fabrication stage often result in the holes being angularly and/or linearly mismatched when the parts are assembled. Match-drilling is an expensive process that requires additional tooling and substantial time during the assembly stage, thus unfavorably impacting product manufacturing flow and cost.
There are many designs of structural assemblies including bolted-bonded joints well known in the art; however, considerable room for improvement remains.